1. Field of the Invention
The present invention relates to an apparatus for conducting a hydrothermal carbonization reaction. More particularly, the apparatus includes a reaction tank, which is connected with a steam generator to receive hot steam, and connected with a mixing tank to receive biomass, by way of a feed pipe, and which is connected with a buffer tank to drain off a slurry that forms in the reaction tank from hot steam and biomass.
2. Description of the Related Art
Such an apparatus is already previously known from DE 10 2011 001 108 A1. There, a hydrothermal carbonization reaction takes place in a reaction tank that is charged from a mixing tank or pre-heating tank. The mixing tank is connected with the reaction tank by way of a solids pump, which conveys the biomass into the reaction tank after a pre-treatment, at a lower pressure and a lower temperature in comparison with the reaction conditions in the reactor. Such a mixing tank is designed for preparing more or less one batch, and then being emptied completely into the reactor.
The actual carbonization reaction then takes place in the reaction tank, under a pressure of about 25 bar and at temperatures from 210° C. to 230° C. In this regard, first the structures of the biomass are split up, in order to split the cellulose of the biomass into glucose within the scope of hydrolysis. Afterward, the actual carbonization takes place. In this regard, mixing of the biomass takes place, as does feed of hot steam, in order to increase the water proportion in the mixture and to form a slurry, in which the carbonization reaction can take place as effectively as possible. Finally, within the scope of the final condensation, the carbon components, which are water-soluble at first, combine to form larger molecules.
After the reaction, the earlier embodiment of the method provides for a buffer tank into which the slurry, which has reacted completely, is brought out of the reaction tank. There, the slurry is once again slowly cooled at a lower pressure level.
Ultimately, the method provides for converting biomass to biocoal, an energy source. In order to work as effectively as possible, as much energy as possible should be saved during the process. Furthermore, it is important to optimize the capacity utilization of the system, in order to work as effectively as possible in this regard, as well.